鄂尔多斯盆地中南部中侏罗世延安期沉积体系及岩相古地理演化  

Depositional System and Paleogeographic Evolution of the Middle Jurassic Yan'anian Stage in the Central and Southern Ordos Basin

作　　者：时志强[1] 韩永林[2] 赵俊兴[1] 杨阳[2] 冀小林[2] 

机构地区：[1]成都理工大学沉积地质研究所,四川成都610059 [2]长庆油田公司勘探开发研究院,陕西西安710000

出　　处：《地球学报》2003年第1期49-54,共6页Acta Geoscientica Sinica

摘　　要：依据新的地层划分方案及大量钻井、露头及岩芯资料 ,详细研究了鄂尔多斯中南部地区中侏罗世延安期沉积体系、岩相古地理特征及演化。认为延 10期为冲积扇 河流沉积体系 ,低弯度砾砂质河道发育 ,盆地内存在多个古地貌高地 ,4条水系汇入甘陕主河 ;延 9至延 6期为多源河湖三角洲沉积体系 ,具大三角洲平原、中三角洲前缘和小前三角洲的特征 ,三角洲平原及前缘的位置不断向湖区推进 ;延 4+5期为网状河 残余湖泊沉积体系 ,湖泊淤塞 ,水体变浅。延 9至延 4+5期网状砂质河道发育 ,西部地区广泛发育平原沼泽煤系沉积。Based on the new stratigraphic division draft and large quantities of drilling, outcrop and core data, the author has studied in detail depositional systems, paleogeographic characteristics and evolution of the Middle Jurassic Yan'anian Stage in the central and southern Ordos Basin. It is held that the fan fluvial sedimentary system was predominant and gently curving calculous-arenaceous fluvial channels were developed at the first substage of the Yan'anian Stage, i.e., Yan 10 substage. There were several paleogeomorphological highlands and 4 rivers running into the Ganshan River at Yan 10 substage. From Yan 9 to Yan 6 substage, there was the fluvial lake delta sedimentary system in the basin which had relatively large delta plain, middle delta front and comparatively small prodelta. At Yan 4+5 substage the braided river and remaining lake sedimentary system was predominant and the lake was silted up. Braided arenaceous fluvial channels were developed, and paludal coal-bearing sediments were well developed from Yan 9 to Yan 4+5 substage in the western part.

关 键 词：鄂尔多斯盆地 侏罗世 延安期 沉积体系 岩相古地理 沉积盆地 

分 类 号：P544.4[天文地球—构造地质学] P512.2[天文地球—地质学]